Definition of

Alternate Interior Angles

When two lines are crossed by another line (the Transversal), a pair of angles
• on each of those two lines
• on opposite sides of the transversal
• but inside those two lines
are called Alternate Interior Angles.


When the two lines are parallel Alternate Interior Angles are equal.

There are actually two pairs, click on "Alternate Interior Angles" below to see.

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